The Polar Bear Explorers' Club

The beginning was absolutely horrible.
We have a sassy 12 years old girl who wasn't allowed to do the only thing she wanted to do, but she didn't do anything similar on a small scale, she wasn't training to become an explorer or anything like that.
We have the horrible aunt who tries to force the girl into a mold.
We have a wonderful dad who goes against everything to make his little girl happy.
Her best friend is this boy who is a bit Autistic (or behaves like one), and she is the only one who understands him, appreciates him, and likes him.
And then we get the Draco Malfoy copy enemy.
It doesn't get any better until about 1/3 of the book when the circumstances lead to the kids to be forced to take care of themselves. Then they manage to clear up most of the cliches, tropes and caricatures, and it ends in a rather OK note.

For some reason, they use wolves as sled dogs. Not actual dogs.
And they have unicorns. Not horses.